The 1910HK/RR two-component system is essential for the virulence of Streptococcus suis serotype 2

- The role of the 1910HK/RR two-component system in the virulence potential of S. suis 2 was investigated.
- The 1910HK/RR two-component system was involved in S. suis 2 adherence and invasion.
- The virulence of ∆1910HK/RR was significantly attenuated in mice and pigs.

Streptococcus suis serotype 2 is a major zoonotic pathogen, and the two-component system plays an important role in bacterial pathogenesis. The present study targeted the 1910HK/RR two-component system of S. suis 2. A 1910HK/RR deletion mutant (Δ1910HK/RR) and the corresponding complementation strain (CΔ1910HK/RR) were constructed in S. suis 2 strain 05ZYH33. 1910HK/RR deletion had no effect on S. suis 2 growth, but significantly inhibited the adherence and invasion of S. suis 2 to HEp-2 cells. Analysis of the role of 1910HK/RR in murine and pig infection models demonstrated that 1910HK/RR played a distinct role in the virulence of S. suis 2. In addition, deletion of 1910HK/RR significantly impaired the survival of 05ZYH33 in human blood. These data provided important insights into the pathogenesis of S. suis 2.